An elevating work platform conventionally consists of a base, an extending structure (for example a boom or other lifting structure) mounted on the base that may be articulated and/or telescopic, and an operator cage that is attached to the end of the extending structure. The operator cage provides the operator with an enclosed and protected area in which to stand while operating the machine. The cage also provides the operator with a platform from which to work when the cage is elevated. The base may be either static or mobile.
A safety hazard can occur both during operation of the platform and also when a MEWP is driven, as the operator may not notice an overhead obstruction and may be pressed against the control console, which in turn could lead to injury or death. Similar risks may also arise in other machines, for example telehandlers and forklifts, in which an operator cage is fitted as an attachment to the load-bearing forks.
An operator cage system that addresses this safety issue is described in international patent application WO2009/037429A, in which the control console is protected by a system that detects a force applied to the console or a handrail or support in the vicinity of the console. If the operator is pressed against the console, this activates a safety switch, which in turn interrupts the drive system of the lifting mechanism (and, if applicable, of the wheels) to prevent further movement of the cage, thus avoiding serious injury to the operator. However, a negligent operator may also be tempted to try to override the system by disconnecting the safety switch or jamming an object underneath the handrail or support to prevent it from being activated.
Other safety systems are known that use a mechanical obstruction sensor. However, as this sensor is obvious in the sense that it can be easily seen by the operator, this may encourage the operator to act carelessly, thinking that the system will protect him from accidents.
It is an object of the present invention to provide an operator cage that mitigates at least some of the aforesaid disadvantages.